Transmission control



Feb. 6, 1945. I P. ORR

TRANSMISSION CONTROL 5 Sheets-Sheet 2 Filed June 19, 1942 I 7 [III] Il/II I00 r Feb. 6, 1945. r P. ORR 2,368,858

TRANSMISSION CONTROL Filed June 19, 1942 5 Sheets-Sheet 3 fill/677.2 27"Pal 772 67" Patented Feb. 6,1945 1 UNITED STATES PATENT- orricjizTRANSMISSION CONTROL 'Paln er Orr, Muncie, Ind., assign'or to Borg-Warner Corporation, Chicago, 111., a corporation of Illinois ApplicationJune 19, 1942, Serial No. 447,617

Claims.

This invention relates to change speed transmissions and'pa'rticularlyto a, control mechanism therefor. It is particularly adaptable tomulti-speed transmissions having a plurality of shiftable elements. Forpurposes of illustration it will be described with eference to atransmission which is disclosed in J. M. Simpson Patent No. 2,324,403,dated .July 13,1943. This invention is in the natureof an improvementover the control mechanism described in my Patent'No. 2,328,227, datedAug. 31, 1943.

In the prior application referred to, a control mechanism is disclosedwherein three shift rails and a cross rail are sointerlocked that anyrail not shifted cannot be accidentally jarred out of place. Theinterlockingmeans there disclosed comprises beans suitably idisposedbetween the" rails and housing. i

The principal object of this invention is to provide in a multi-speedtransmission having three or more shiftable devices, an interlockmechanism for the shift devices wherein the interlock mechanism isoperated directly by the shift member itself.

A more specific object of this invention is to provide an interlockmechanism for a transmission employing three shift rails and a, selectormember wherein one of thevrails is normally held against movement by alatch, said latch being releasable by the shift member.

These and other objects and features of this invention will become,apparent from the followmovement of the various gear Said gear II is inconstant mesh with a gear I2 mounted to drive a countershaft I3 on whichare also drivablymounted gears 14 and [5. A fourth gear 16; is slidablymounted on-c'ountershaft 13 as is. likewise a fifth gear l-"l. Saidgears l3 and 7 ll areprovided with flanges l 8" and I9 respectively overwhich is fitted a U-shaped yoke such that gears l6 and I! must movetogether axially but may rotate independently of one another. Gear IT isprovided with internal splines Z'lfwhich, when said gear ll is in theposition shown, mesh with external splines 22 on countershaft I 3; GearI5 is provided on one side with internal clutch teeth 23 whichareadapted to be engaged by external clutch teeth 24 on gear 16 when saidgear I 6 is moved to the left (Fig. 1).

1 gear H, and to the right to engage clutch teeth,

In constantmesh with gears I 4 and 15 are gears Hand-26 respectivelywhich are freely mounted on a driven shaft 21. A third gear 23is'likewise freely mounted on driven shaft 21.

Drivably mounted on shaft 21 are hub members 29 and 30 of clutchingdevices 3i and 32 respectively, the function of each of which isselectively to.

connect gears ll, 25, 26 and 28 to driven shaft 21 To this end clutchingdevice 3| is provided with an internally toothed collar 33 which may bemoved: to the left toengage clutch teeth 34 on 35 on gear 25. Similarly,clutch device 32* is provided with external teeth 31 and '38 which are,

engageable with internal teeth 39 and 40 respece tively upon movement ofinternally toothed collarv 4| to the left or right of the positionshown.,' Each of said collars 33 and M is of course drivingly secured toits respectiveihub Z9 and 30 so'that when the collar is connected to itsassociated gear, said gear is in effect connected to drive Fig. 5 is afragmentary enlarged section through the controls taken along line 5-5of Fig. v4; and

Fig. 6 is a fragmentary section taken. through the poppets for thecontrol mechanism of Fig. 3,

the section being taken alonglines 56 of Fig. l.

Referring now to Fig. .1 fora brief description of the transmission towhich-this invention is applied,.power is impressed upcn a drive shaftH] from an engine or other source of power. (not shown) to which issecured a drive gear H.

driven shaft 27'. i I

Movement of collar 33 'is controlled by means of a shift fork 42 ridingin a groove 43 in collar 33 and movement of. collar 41 is effected bymeans of a shift fork- 4 3 riding in a groove 45 in-collar 41. v I v i Asecond countershait 46 is provided on which are mounted gears v41 and48, the gears being so arrangedas to rotate together. Gear d'l mesheswith gear 16 and gear 48 meshes with gear 281m shaftZl. i

The .ratios obtainable in the transmission just described are asfollows: 7

' Neutral is obtained by positioning collars 33 and 41 as shown in Fig.1.

Low speed is obtained by sliding collar- 41 to the right sothat teeth 38and 40 are in mesh. Gears i6. and 17 are likewise slid tonthe right sothat the'internal teeth 2| on gear I! engage,

external teeth 22 on countershaft l3. The drive is then from drive shaftl and drive gear II to gear [2, countershaft l3, teeth 22 and 2|, gearl1, gear 28 and clutch device 32 to driven shaft 21.

For the next higher speed, gears I6 and I! remain as shown in Fig. 1, asdoes also clutch device 3l, but collar 4| is slid to the left to engageteeth 31 with teeth 39. The drive is then from drive shaft l0 and drivegear II to gear [2, countershaft I 3, gear [5, gear. 26 and clutch devic12 which is pinned to across rod 13 slidably re- 32 to driven shaft 21.r

For the third speed gears l8 and I1 again remain as shown in Fig. 1,clutch device 32 is moved to the position shown in Fig. 1, that is, withneither gear 26 nor gear 28 connected to driven shaft 2?, and clutchdevice 3! is moved to the right so that collar 33 engages teeth 35 toclutch I gear 25 to driven shaft 21. then from drive shaft l0 and drivegear H to gear 12, countershaft l3, gear 14, and gear;25 to clutchdevice 3] and driven shaft 21.

For direct drive, clutch 32 remains in neutral and gears I6 and 11 againremain as shown in Fig. 1, but clutch device 3| is slid to the left sothat teeth 54 engage collar 33 and connect gear H directly to drivenshaft 21.

Reverse is obtained by conditioning clutch devices 3! and 32 nd for thefirst speed drive but in addition sliding gears 16 and l! to the left toengage teeth 24 with teeth 23; In engaging teeth 24 with teeth 23, gearI! is disconnected from countershaft I3 and hence is free to rotaterelative to the countershaft. The gear train is then from drive shaft l8and drive gear I! to gear [2, countershaft I3, gear '15, teeth 23 and 24to gear I 6 and thence to gear 41 on countershaft 48,. gear 48, gear 28and clutch device 32 to driven shaft 21. The incorporation of the idlergears 41 and 48 efiects a reversal in the driving relation betweenshafts I0 and 27.

The details of the transmission just described are shown and claimed inthe copending application of J. M. Simpson, Serial No. 436,819, filedMarch 30, 1942.

The movement of the hand shift lever required to efiect the variousavailable ratios is shownv in Fig. 2. It will be observed that directand second are on one side of the neutral position and reverse, firstand third are on the opposite side; Particular attention is directed tothe fact that reverse is obtained by first shifting into the posi-' tionfor first speed, then shifting laterally and then shifting again in thesame direction as the shift into first. The means by which movement ofthe shift lever in accordance with Fig. 2 is translated into therequired movements of "the shift devices of the transmission will now bedescribed.

Referring now to the remaining figures, first and second speed shiftfork 44 is shown secured to a shift rail 49 which is slidably retainedin openings 50 and 51 in housing 52. Third and fourth (direct) speedshift fork 42 is connected for movement with a shift rail 53 which isslide ably retained in openings 54 and 55 in housing 52.

Reverse shift yoke '28 is pivotally mounted in one end of a lever 56,the other end of which is retained in a notch 51 in a shift rail 58slidably mounted in openings 59 and 80 in housing 52.

Lever 56 serves to reverse the direction of movement of shift yoke 28with respect .to shift rail 58.

Shift fork 42 is provided with an enlarged end The gear train istained'in suitable openings (not shown) in housing 52. Said cross rod 13is oscillatable about its axis by means of an external lever 16 whichmay I be operated by a manual control (not shown) conveniently locatednear the operator.

The oscillation of cross rod 13 and its associated lever 12 effects aselection of the rails and axial movement of cross rod 13 by suitablemeans (notshown) effects a change in gear ratio by'the axial movement ofthe shift rod selected.

Thus lever 12 may be moved axially to shift rails 48, 53 and'58 ineither direction and may be.

oscillated about its own axis to engage any one ofthe notches H, li'land63. Asis customary in such devices the adjacent. notches must be alignedbefore a cross over'from one rail to an-.

other can be effected and the cross over is effectedwhen the adjacentnotches are in neutral position.

To assist the operator in determining when he has completed the shift toa particular ratio, poppets are used in conjunction with each rail. Thus(Fig. 6) shift rail 45;is provided with a poppet (8, shift rail 53 witha poppet l9 and shift rail 58 with a poppet 80. Each of the poppets isprovided with a spring BI, 82 and 83respectively, so as to resistmovement of the rail out of a predetermined position. Shift rail53 isprovided with notches 84, 85-and 86which cooperate with poppet 19 and,correspond'to third, neutral and direct positions respectively, shiftrail 48 is provided with notches 81, 88 and 89 which cooperate withpoppet l8 and correspond to first speed. neutral, and second speed,respectively, and shift rail 58 is provided with a notch 90 whichcooper-. ates with poppet 88 and corresponds to reverse position of rail58. Movement in either direction from shift rail .49 islimitedby the"bottoms of notches 83 and 1|,and after arail has been shifted out ofneutral position the lugs of the adjacent rails prevent lateral movementof shift lever 12. g

Since no two ratios can be in operation simultaneously, an interlock isarranged between the rails such that when one rail is shifted out ofneutral, the adjacent rail is locked in neutral position. This interlockcomprises opposed notches (see Fig. 6) 94 and 95' on adjacent rails 49and 53 and the usual plunger 96 riding in an opening 9! in housing 52connecting notches 94 and 95'. In the form chosen for illustration,plunger 98 comprises a pair of balls, butit might also be a singlemembersuch as the usual bean. or it may be a pair of membersseparatedlby a spring. In whatever form it may take, plunger plungerlflflriding in an opening 18! which is- I aligned with notches 38 and99.

It will be observed however, that in view of the fact that no shift canbe made until all rails are in neutral, when rail 53 is shifted out ofneutral,

the remaining rails 49 and 58 are in neutralandi hence plunger I iineffective to maintain rail 58 in neutral. jarred, it is possible thatrail 58 will be shifted out of neutral into reverse at the same timethat rail 53' is in third speed or direct. This of course would bedisastrous and an additionalinterlock therefore is provided to take careof such a contingency.

The additional interlock is hown in-detail in Fig. 5, It is comprised ofa pivoted latch I02 mounted in a slot I03 in cylindrical attachment 68which is secured to reverse shift rail 58. Said latch I02 is providedwith a toe portion I04 which normally extends into notch 'II in the pathof l into notch II preparatory to shifting rail 58, lever 12 engages toeportion I04 of latch I02 and rotates the latch clockwise as viewedinFig. 5 against the action of spring I08 to disengage heel. portion I05from slot I06. The disengagement is comvIf'the transmission should beuntil said second element has been'shifted provide one of said two otherspeed ratios, interlock means between said first and. second elements,

interlock means between said second and third "elements, and a latchbetween said third element and said housing and releasable by saidshifter when the shifter engages the third element.

2. In a torque transmitting mechanism having a housing and a pluralityof shiftable elements releasable by the shifter when said shifterenpleted just prior to the completion of the shift of lever 12 intonotch II. With latch I02 freed from housing 52 and rail 58 is thenreadily movable axially to shift into reverse. Latch I02 will bemaintained in a released condition so long as lever I2 is fully engagedin slot II andthis' engagement of lever 12 with slot 1| will obtain aslong as lever 12 is in the position shown in Fig. 5.

No similar latch is required with respect to rail 53 ince as pointed outabove, rail 58 cannot b moved until the rail 49 is moved to the firstspeed position, and when rail 49 is so moved, interlock plunger 96immediately becomes effective to prevent rail 53 from moving. A lockbetween rails 49 and 58 in the first speed position of rail '49 isprevented by an additional notch I09 in rail 49. Thus it will beapparent that with the combination of interlocks described above onlyone rail can be moved at-a time and the operation of the one railautomatically prevents the remaining rails from moving.

It is understood that the foregoing description is merely illustrativeof a preferred embodiment of the invention and that the scope of theinvention therefore should not be determined thereby but should bedetermined instead by the appended claims.

I claim:

I. In a torque transmitting mechanism having a housing and a pluralityof shiftable element located therein, said elements comprising a firstelement for shifting into either one of two ratios, a second element forshiftinginto either one of two other ratios, and a third element forshifting into reverse, means for effecting a mutually exclusiveoperation of said elements comprising a shifter for engaging theelements, means for moving said shifter across said elements forselecting the elements, means for preventing engagement of said thirdelement by said shifter located therein, said elements comprising afirst element for shifting into either one of two ratios, a secondelement for shifting into either one of two other ratios, and a thirdelement for shifting into reverse, means for effecting a mutuallyexclusive operation of said elements comprising a shifter for engagingsaid elements, means for moving the shifter across the elements toselect one element, interlo'ck means between the first and secondelements effective to lock one of the elements when the other is shiftedto provide one of said ratios, means for preventing engagement of thethird element by the shifter until the second element has been shiftedto provide one of said two other ratios, interlock means between thesecond and third elements for preventing movement of the second elementafter it has been shifted to provide one of said two other ratios andsaid third element has been shifted to provide reverse, and latch means,betweenthe third element and the housing, said latch means. being gagesthe third element.

3. In a torque transmitting mechanism having a housing and a, pluralityof shiftable elements therein, means for efiecting a mutually. exclusiveI operation of said elements comprising a shifter for engaging saidelements, meansjfor moving the shifter across the elements to select asingleelement, interlock means between adjacent elements and additionalinterlock means between one element and the housing, said one elementhaving.

a slot therein for receiving the shifter element and another slotcommunicating with the firstmentioned-slot, a pivoted latch in saidsecondmentioned lot having a toe portion extending into the shifterslot, and a heel portion, a slot in the housing engaged by the heelportion to prevent axial movement of said one element, and resilientmeans normally urging said latch toward the slot in the housing. v

4. In a torque transmitting mechanism havfor effecting a mutuallyexclusive operation of said elements comprising a shifter for engagingsaid elements, means for moving the shifter across the elements toselect one element, interlock means between adjacent elements, and

means for preventing an unwanted shift into reverse, said last-mentionedmeans comprising a slot in the housing, a latch in the reverse shifterelement and means normally urging said latch into engagement with theslot, said slot being disposed transversely of the axis of movement ofthe reverse element. I

5. A torque transmitting mechanism as described in claim 4, and means onthe latch "en-' gageable by the shifter when the mechanism is

